Let-off for terry looms



April 17, 1928. 1,666,872

H. A. DAVIS LET-OFF FOR TERRY LOOMS Filed Feb. 23, 1924 3 Sheets-Sheet 1lnvenTor.

Harry A. Davis by/wMWJ M ATTys.

April 17, 1928. 1,666,872

H. A. DAVIS LET-OFF FOR TERRY LOOMS Filed-Feb.23, 1924 5 Sheets-Sheet 2lnvenTor.

Harry A. Davis WWW AITyS.

April 17, 1928. 1,656,872

' H. A. DAVIS LET-OFF "FOR TERRY LOQMS Filed Feb. 23, 1924 3Sheets-Sheet 3 Fig.3.

Patented Apr. 17,

LE, MAssAcH snTTsQAss IGNoa To DRAPER conrona- MASSACHUSETTS, ACORPORATION or MAINE.

HARRY A. DAVIS, OF HOPEI JA TION, OF HOPEDALE,

LET-OFF s P TENT OFFICE m. TERRY Looms.

Application filed February as, 1e24.,seria1 n 694,557.

This invention relates. to the terry loom such'as commonly employed ,forweaving double pile fabrics employed in the manufacture of Turkishtowels. 5 in the weaving of such It is important fabric that there shallbe woven sections of plain fabric as well as sections of pile fabric.tlons are alternated in These secstripes as desired and the width andposition of the sections is usually determined by which automaticallygoverns the change from plain to t the terry loom there One set iscarried by warp beam suchas e The other set known carried by and warpbeam and these erry weaving and vice versa.

a pattern mechanism In are two sets of warps. and runs off from amployed in any loom. as the terry warps is runs off from a separateterry terry warps form the loops of the pile fabric.

The present invention I provision of means for "effecting object the hasfor its chief the control of the terry warps so as to securesatisfactory results especially in the weaving of the plain sections ofthe fabric.

The object of the invention is further to provide a friction letwarp otfmeans for the terry beam which shall exert an intensified or extraamount of friction during'the weaving of the plain sections of fabricand thus insure an even and regular quality of plain weaving.

The object of the invention is further .to provide means for controllingthe iQITSlOIl on the terry warps to make it substantial sion upon theground warps during insure a. regular plain weaving and thus weave.

The object of provide means during plain weaving so as ly the same asthe tenplain the invention is further to for insuring that the terryloops shall be maintained of uniform and full length to theend of thezone of terry weaving and shall not decrease in length adjacent the zoneof pla The object of the invention is provide an actuator for ficationof the amou terry warp jected to in weaving.

further to effecting the intensint of friction on the beam which shallnot be subany strain due to the normal or predetermined amount offriction on the terry warp beam imposed during terry weaving.

The object of the invention is further to provide a combinatio for theterry Warp bea 'for the terry warps n of m and a positive let-offtogether with means vember 25,

the construction shown in a. friction let-off acting to render thepositive let-01f active and to cause the friction let-off to exert apredetermined amount of frictionnpon the full' forward stroke beat ofthe reed for forming the terry loops, to cause the friction let-ofl toexert the said predetermined 9 amount of friction and to render thepositive let-off inactive during the partial forgreater amount offriction and to render the positive let-off inactive during plain weavmgg Y These and other objects and features of the invention will appearmore fully from the accompanying description and drawings and will beparticularly pointed out in the claims.

The invention in its preferred form is shown as applied to a familiartype of terry loom such, for example, as that illustrated in the patentto Merrill No. 1,322,715, No

well known and familiar to those skilled in the art it is only necessaryherein to illustrate and describe such a. loom in so far as it isparticularly concerned with the present invention.

In the drawings:

Fig. 1 is a front'elevation of the'end of the terry warp beam, itssupport,'and certain of the mechanism associated therewith and necessaryto a disclosure of the inven-. tion.

Fig. 2 is a side elevation of a portion of Fig; 1. 1

Fig. 3 is a side elevation partially broken away and partially invertical cross section showing therear portion of the loom.

Fig. tis a detail in side elevation showing the opposite end of theterry warp beam.

The loom comprises the usual side frames 1. These side frames rest uponthe floor 2 and are connected by the usual girders and support the usualshafts and rods.

The warp beam 3 carrying the I ground warps is supported by its shaft 4at the rear of the loom frame in the usual manner. The ground warps 5extend from this warp beam over the usual whip roll 6 forward throughthe usual harnesses, reed, and so forth (not shown) to the front of theloom. The control of and tension upon the ground warps 5 nism such asemployed in any regular loom.

1919. As this type of loom is c is provided by any suitable meehaof theterry warp beam 11.

' main under the usual tension.

Standards 7 and '8 extend up from the side frames at the rear of theloom. These standards at the top are provided I with roller bearings '9upon which rest the trunnions 10 The terry warps 12 extends from theterry warp beam downwardly through a positive let-off mechanism of atype similar to that shown in the patent to Davis No. 1,322,671,November 25, 1919, and then forwardly along with the ground warps. I

In thistype of 100111 the terry weaving is effected by varying theforward extent of the beat up movement of the reed. For several picksthe reed has only a partial forward stroke toward the fell of theclotlrso that a gap. is leftbe'twe en the picks and the fell. The reedis then given a full forward stroke to beat up the several picks atonce. (hen this full beat up the reed takes place the terry warps areunder a predetermined but slight tension and are usually positively fedforward or let off from the warp bea-m whereas the ground warps re-Hence the portions of the terry warps which are between the group ofpicks and the fell of the cloth are looped on both sides of the fabricas the full beat up of the reed occurs.

When a section of plain weaving is made the reed has its full beat upmovement fol" I lowing each pick and hence no loops are formed in theterry warps. But diliiculty has been experienced in making a perfectplain weave because of the inequality of tension betweenthe terry warpsand the ground warps. The present invention provides for securing therequisite tension on the terry warps to correspond with that on theground warps and thus insure a regular and perfect plain weave while atthesame time it provides for or permits the requi ite tension andlet-off of the terry warps during terry weav- It is particularlydesirable that the terry loops shall be maintained of the same length orheight (throughout each zone of terry weaving. Heretofore difficulty hasexisted in this respect when the clnuige takes place particularly fromterry weaving to plain weaving because the terry loops have been drawndown or shortened. The present invention in.-;ures that the terry loopsshall remainof the same length clear upto the zone of plain weavingandshall not be shortened. or drawn down when the change takes place,

Various mechanisms may be provided for giving the partial and fullforward strokes to the reed and for the purpose of disclosing thepresentinvention it is assumed that such means as shown in the Merrillpatent above mentioned are to be used. construction the control ofthechange from In that plain weaving to terry weaving and vice versa iseffected through a pattern mechanism including the pattern chain 13. Anactuator 1 1 is pivoted at 15 and has a connector 16 which extends toand controls the beatarp motion. It. is assumed that when a riser 17 ofthe pattern chain holds the actuator 141 elevated the beat-up motionfunctions to perform plain weaving and that when the riser l7 passesfrom beneath the actuator l l allowing it to fall to the position shownin dotted lines in Fig. 1, the beat-up motion functions to perform terryweaving. v

In the construction illustrated the terry warps are under the controloftwo separate mechanisms, first, a positive let-off mechanism of thetype shown in the Davis intent 1,322,671 above niei'itioned, and second,a

friction let-off which acts to e iert'a predetermined constant amount offriction. du'riii-g terry weaving and during plain weaving. k

The positive let-oil mechanism is located between the terry warp beaman'dthe reed. This mechanism, whichniaybe any. suitable construction,'is'show'n in Fig. 3 as generally similar to that of the beforementioned Davis Patent No. 1,322,671. The terry warps 12 run from theterry warps beam under an idler roll 18 and thence around the roughsurfaced let-off roll 19 thence over and under the idler roll 20 andthence forwardly to the harnesses. 'A gear 21 is fast with the roll 19and is actuated by a pinion 22 on a shaft 23. The shaft carries a.ratchet wheel 24c which is actuated by a springpressed, pawl 25. Thispawl 25 is pivoted to one end of a pivoted pawl lever 26 the other endof which is connected by a link 27 to a bell crank 28 pivoted at 29.This bell crank has a lost motionronn' ction 30 with a rod 31 adjustablyconnected at 32 to a crank arm 33 on the beat 'up mo tion rock shaft 8 1corresponding to that in the before mentioned Merrill and Davis patents.Inthis type of mechanism a cam lever 35 is loosely hung at itsfront end'on the shaft 34 and carries-a at its rear end a'roll 3G traveling inthe groove 37 of the cam 38 secured to the hack shaft 39. arranged to becoupled to and uncoupled from the shaft 35 and during theterry wcavingit remains coupled to the shaft 3% and hence the shaft is rocked hackand forth every revolution of the cam 38. This cam is so shaped that theshaft is rocked every full beat-up stroke of the reed or in theillustrative instance at every third forward beat of the lay. Duringplain weaving the a greater amount lever 35 is uncoupled from the shaft,so that This lever 35 is ing the partial forward strokes of the reed interry weavingbecause the cam groove 37 is so shaped that no movement isgivento the shaft 34 and consequently to the rod" 31 during thosestrokes.

It will thus be seen that the positive let-off mechanism is renderedinactive during plain weaving and also during the partial forwardstrokes of the reed in terry weaving-but is rendei'edactive upon thefull forward stroke beat of the reed for forming the terry loops.

The friction let-off is shownin detail in Figures 1 and 2 and isconveniently applied to the warp beam. For this purpose the terry warpbeam 11 is provided at one head with a drum 40. A flexible friction band41 surrounds the greater portion of the periphery of the drum and isarranged so that its tension or pressure on the drum maybe adjusted asdesired and so that a predetermined amount 'of tension or friction maybe exerted during terry weaving or preferably j ust sufiicient toprevent over-running. This friction let-off mechanism is also arrangedto act during plain weaving to give any required degree of tension tothe terry warps and thus produce the same tension on the terry warps ason the ground warps and in addition this mechanism is arranged'to exertthe normal or predetermined tension during terry weaving so as to enablethe terry warps to be under the control of the positive let-offmechanism by which the terry warps are fed forward during the formationof the loops. In the construction illustrated a bracket 42 is secured tothe inner faceof the standboss 48 is adjustably secured by means of a'set screw 49 to the inner end of the rod and has projectinginwardlytherefrom 'a flat apertured head 50. A rod 51 passes through theaperture-in the head and: has a T shaped head 52 resting in a loop atoneend of theband 41. This rod at its'op'posite end is threaded andprovided with a thumb nut '53. A spring'54 extends between the nut andthe head 50. v

The construction at the other end of the band 41 is similar. In thiscase the boss 55 nut and the head. 'juncts thus constitutes a movablesupport the nut and the head.

is 'pivotally mounted at 56 on the bracket 42 and has an arm 57projecting laterally and connected by a link 58 with the actuator 14.

The boss 55 has adjustably secured therein by the set screws 59 the rod60 carrying at its inner end the boss 61 provided with a fiat aperturedhead 62. A similar" rod 63'provided with a T-shaped head engages a loopin the other end of the band 41, passes through the aperture of the head62 and 1 carries the thumb nut '64 threaded thereon with the spring 65interposed between the I The boss 55 with its adfor the end of thefriction band;

"The boss 55 is shouldered at 66 and this shoulder cooperates with ashoulder 67 and a sleeve fast to the bracket 42 so as to limit theupwai-dinovement of the rod 60 and the downward movement of the arm 57.Consequently there can be no strain on the actuator 14 or the patternnechainism when these shoulders: are in engagement which is the normalcondition during terry Weaving.

Since the direction of rotation of the terry warp beam and its drum 40is toward the spring 54 this spring may be of less strength than thespring 65. The thumb nuts 53 and 64 enable the amount of frictionapplied to the drum 40 and consequently the tension on the terry warpsto be adjustedas required.

It is desirable also in order to balance the construction to provide asimilarnormal amount or predetermined amount of friction at the oppositeend of the terry-warp beam and forthat purpose the construction. shownin Fig. 4 may be employed. Therein a drum v68 similar to the drum 40. issecured to the warp beam. A flexible friction band 69 encircles .thegreaterv portion of this drum and is secured at one end 70 too. lever 71fulcrumed at 72 on the standard 8. A vrod 73 provided with a. T-shapedhead engages a loop in the other end of the band 69, passes through anaperturein the other end of the lever 71 and carries a thumbnut 74threaded thereon with a. spring 75 interposed between This enables thetension on the band 69, and consequently the friction exerted upon thedrum '68, to be adjusted as desired.

\Vhen the change takes place from terry weaving to plain weaving theriser 17 of the pattern chain raises the actuator 14 from its normalposition shown in dotted lines in Fig. 1 to the full line position.Immediately through the link connection 58 the arm 57 is rocked thussuddenly compressing the spring 65 and intensifying the'ainount offriction applied to the drum 40. This action takes 1. A terry loomcomprising a terry warp beam, a friction let-oil" for the terry warpbeam, means acting to cause said let-off to exert a predetermined amountof friction on the terry warp beam during terry weaving, automaticallycontrolled means for changing from terry to plain weaving, and meansacting simultaneously with such a change and prior to the first beat-upof plain weaving to effect apredetermined intensification of the amountof friction exerted on the terry warp beam, thereby to maintain theterry loops of uniform and full length to the end of the zone of terryweaving and to begin the zone of plain weaving perfectly.

2. A terry loom comprising a ground warp beam and means for producingthe required tension on the ground warps, a terry warp beam, a frictionlet-off for the terry warp beam, means acting to cause said let off toexert a predetermined amount of friction on the terry warp beam duringterry weaving, automatically controlled means for changing from terry toplain weaving, and means acting simultaneously with such a change andprior to the first beat-up of plain weaving to effect an intensificationof the amount of friction exerted on the terry warp beam sufficient tomake the tension on the terry warpsto correspond to the tension on theground warps, thereby to maintain the terry loops of uniform and fulllength to the end of the zone'of terry weaving and to begin the zone ofplain weaving with equal tension on theterry and ground warps.

3, A terry loom comprising a terry warp beam, a friction let-off for theterry warp beam, means acting to cause said let-off to exert apredetermined amount of friction on the terry warp beam during terryweaving, means for adjusting the said predetermined amount of friction,automatically controlled means for changing from terry to plain weaving,and means acting simultaneously with such a change and prior to thefirst beatup of plain weaving to effect a predetermined intensificationof the amount of friction eXerted'on-the terry warp beamythereby "tomaintain the terry loops of uniform and full length to the end of-thezone of terry weaving and to begin the zone of plain weaving perfectly.

4:. A terry loom comprising a terry warp beam,a friction let-off for theterry warp of friction exerted on the terry warp beam and actingsimultaneously with the change from plain to terry weaving and prior tothe first beat-up of terry weaving to restore the said predeterminedamount of friction on the terry warp beam, thereby to maintain the terryloops of uniform and full length throughout the zone of terry weavingand to "effect perfect plain weaving throughout the zone of :plainweaving.

5. A terry loom comprising a terry warp beam, a friction let-off for theterry warp beam, means acting to cause said let-off to exert apredetermined amount of friction on the terry warp beam, an actuatorwhich acts to effect-the change from terry weaving to plainweaving andvice versa, and means operated by and simultaneously with said actuatorupon effecting the change from terry weaving to plain weaving and priorto the first beat-up of plain weaving to ef feet a predeterminedintensification of the amount of friction exerted'on the terry war-pbeam and upon effecting the change from plain to terry weaving and priorto the first beat-up of terry Weaving to restore the saidPIGClBtGIIIIlDG Cl amount of friction on the terry war-p beam, therebyto maintain the terry loops of uni-- form and full length throughout thezone of terry weaving and to effect perfect plain weaving throughoutthe, zone of plain weaving. I

6. A terry loom comprising a terry warp beam, a friction let-off for theterry warp beam, means acting to cause said friction letoff to exert apredetermined amount of friction on the terry warp beam during terryweaving and a greater amount during plain weaving, apositive let-offmechanism for the terry warp located between the terry warp beam and thereed, and means acting to render said positive let-off mechanism activeat the full. forward stroke beat of the reed in terry weaving and torender it inactive during the other forward strokes of the reed in bothterry an'diplam weaving whereby the :positive let-oif acts on the terrywarps upon the full ,forwa-rd stroke beat of the reed in formingthe'terry loops, the fricti'onlet-oif exerts the said predeterminedamount of '7. A terry loom comprising a terry warp beam, a frictionlet-off for the terry warp beam, a positive let-off mechanism for theterry warp located between the terry warp beam and themed, and meansacting to render the positive let-off active and to cause the frictionlet-oif to exert a predetermined amount of friction upon the fullforward stroke beat of the reed for forming the terry loops, to causethe friction let-off to exert the said predetermined amount of frictionand to render the positive let-off inactive during the partial forwardstrokes of the reed in terry weaving and to cause the friction letoif toexert a greater amount of friction and to render the positive let-offinactive during lain Weaving.

8. A terry loom comprising a terry warp beam, a friction let-off for theterry warp beam, means acting to cause said let-ofi to exert apredetermned amount of friction on the terry warp beam, an actuatorwhich acts to effect the change from terry weaving to plain weavingandvice versa, means operated by said actuator upon effecting the changefrom terry weaving to plain weaving to intensify the amount of saidfriction and upon effecting the change from plain weaving to terryweaving to restore the said predetermined amount of friction, and meansfor preventing the friction let-off from exerting any strain on theactuator during terry weaving.

9. In a terry loom, a terry warp beam, a drum rigid and concentrictherewith, a frame for supporting the beam, a friction band partiallysurrounding the drum, a tension spring connecting one end of the band tothe frame, a support movably mounted on the frame,

change suddently to move thesupport a predetermined distance against thetension of the second spring, thus immediately to effect a predeterminedintensification of the, friction exerted by the band on the drum duringplain weaving. I

10. In a terry loom, a terry warp beam, a drum rigid and concentrictherewith, a frame for supporting the beam, a friction band partiallysurrounding the drum, means connecting the end ofthe band toward whichthe drum is rotated to the frame, a support movably mounted on theframe, a tension spring connecting the other end of the band to thesupport, automatically controlled means for changing from terry to plainweaving, and means acting simultaneously with such a change suddently tomove the support a predetermined distance against the tension of thespring thus imme'd iatel 'to effect a'predetermined intensification othe friction exerted by the band on the drum during plain weaving.

11. In a terry loom the construction defined in claim 9 together withmeans for limiting the movement of the support in the opposite directionto that which it is moved to intensify the friction whereby a minimumpredetermined amount of friction is exerted by the band on the drumwithout exerting strain on the means for moving the support.

In testimony whereof, I have signed my name to this specification. I

' HARRY. A. DAVIS.

